Packaging machine and method of forming packages



Sept. 22, 1970 w. E. YOUNG ET AL PACKAGING MACHINE AND METHOD OF FORMING PACKAGES Filed Dec. 22, 1967 12 Sheets-Sheet 1 INVENTORS WILLIAM E. YOUNG ROBERT 0.WOLFELSPERGER HARRY J. JOHNSON PATRICK J.P!NTO CHARLES V.WALLA E TORNEY p 22, 1970 w. E. YOUNG ET AL 3,529,396

PACKAGING MACHINE AND METHOD OF FORMING PACKAGES l2 Sheets-Sheet 2 Filed Dec. 22, 1967 R s E m m m n E C E SN A VGEOOL NYNFSTA OOH! W O O S M T W M m R ima M R Hn I: L I'Il l ll hull H II G x ow wummn n n 1 I J A. I 5 0w I H rufimnu l .mm I mm m m k.@ on

Y BY ATTORNEY Sept. 22, 1970 w, YOUNG ET AL PACKAGING MACHINE AND METHOD OF FORMING PACKAGES Filed Dec. 22, 1967 *2 Sheets-Sheet 3 Hllllllllll INVENTORS WILLIAM EvYOUNG ROBERT O. WOLFELSPERGER HARRY J. JOHNSON PATRICK J. PINTO CHA ESV.WAL ACE ATTORNEY Sept. 22, 1910 w., E. YOUNG E AL PACKAGING MACHINE AND METHOD OF FORMING PACKAGES Filed Dec. 22, 1967 i2 Sheets-Sheet t m Vol in m 5 m m S s u km h H mm W m H H NQ'M H H T w ov l u N L I WM 5 WWE III mm III II J! .IT mu W WW I I! I Y m l HMH ll 5.0 n mm :1 I M II L nK Wn L mo f ll mm I. u r w; mm Q m E HARRY J.JOHNSON PATRICK J. PINTO CHAR ES VWAL ACE ATTORNEY Sept. 22, 1970 w. E. YOUNG ETAL 3,529,396

PACKAGING MACHINE AND METHOD OF FORMING PACKAGES Filed D60. 22, 1967 12 Sheets-Sheet 5 1 N VEN TORS WILLIAM E. YOUNG ROBERTQWOLFELSPERGER HARRY J.JOHNSON PATRICK J.P!NTO CHAR ES VvWA ACE BY ATTORNEY Sept. 22, 1910 W. E. YOUNG ET L PACKAGING MACHINE AND METHOD OF FORMING PACKAGES l2 Sheets-Sheet 6 Filed Dec. 22, 1967 mull uuul u INVENTORS WILLIAM E.YOUNG ROBERT O. WOLFELSPERGER HARRY J.JOHNSON PATRICK J. PINTO CHAR ES v. WALLACE ATTORNEY Sept. 22, 1970 'w. E. YOUNG ET AL 3,529,396

PACKAGING MACHINE AND METHOD OF FORMING PACKAGES Filed Dec. 22, 1967 12 Sheets-Sheet 7 I N VEN TORS WILLIAM E.YOUNG ROBERT O WOLFELSPERGER HARRY J. JOHNSON PATRICK J. PINTO CHARLES V. AL ACE BY 7 ATTORNEY Sept. 22, 1970 w. E. YOUNG AL 3,5 ,3

PACKAGING MACHINE AND METHOD OF FORMING PACKAGES Filed Dec. 22, 1967 12 Sheets-Sheet 8 I I I40 l2! 4 I 2 1 I20 l 14: H5- :22 :19 C I :20

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l/llllllikflfl4'. .'fl('4'-'('lfl V [\IVENTORS Fig. WILLIAMEYOUNG ROBERTOWOLFELSPERGER HARRY J. JOHNSON PATRICK J. PINTO WES V.WAL ACE BY 97 3 ?Arron-ev l2 Sheets-Sheet 9 INVENTORS W. E. YOUNG ET L WILLIAM E. YOUNG ROBERTO WOLFELSPEFIGER HARRY J.JO HNSON PATRICK J; PINTO CH LES VW LLACE PACKAGING MACHINE AND METHOD OF FORMING PACKAGES Filed Dec. 22. 1967 Sept. 22, 1910 fi -J2 rags ll Sept. 22, 1970 w. E. YOUNG ET AL PACKAGING MACHINE AND METHOD OF FORMING PACKAGES l2 Sheds-Sheet 10 Filed Dec. 22, 1967 r l 232 I 4 I99 7 g 1 I 213- III I 20 204 2!! 2 L l 6 20? 207 WM i 'i 2:0- 08 i H I: I LT i r --r"1 235 I Q-'' |-ih l l/ T l I I I a I l 234 I A 1 z I l I I l I I I I l l 3E I l l 209 222 an 7 l 1 INVENTORS.

WILLIAM E. YOUNG ROBERT O. WOLFELSPERGER HARRY J. JOHNSON PATRICK J. PINTO V. WAL ACE Sept. 22, 1970 w. E. YOUNG ET AL 3,

PACKAGING MACHINE AND METHOD OF FORMING PACKAGES Filed Dec. 22, 1967 12. Sheets-Sheet 11 I N VENTORS.

WILLIAME. YOUNG I ROBERT o. WOLFELSPERGER HARRY J. JOHNSON PATRICK J pmro CHA ES V.WAL CE svmiv ATTORNEY Sept. 22, 1970 w. E. YOUNG ET AL PACKAGING-MACHINE AND METHOD OF FORMING PACKAGES Filed Dec. 22, 1967 12 Sheets-Sheet 12 FIG- 19 INVENTORS R B E E m o w. w n G A A NEOOL F TL mmmm ww O JW. MT KE NW uwmmm I H W HmC United States Patent 3,529,396 PACKAGING MACHINE AND NETHOD F FORMING PACKAGES William E. Young, Stamford, Conn., and Robert 0.

Wolfelsperger, Fairfield, Harry J. Johnson, West Paterson, Patrick J. Pinto, Cedar Grove, and Charles V. Wallace, Glen Rock, N.J., assiguors to William E. Young, Stamford, Conn.

Continuation-impart of application Ser. No. 548,517, May 9, 1966. This application Dec. 22, 1967, Ser. No.

Int. Cl. B65b 31/02 US. C]. 53-22 44 Claims ABSTRACT OF THE DISCLOSURE The machine seals a series of delivered bottom and top boards together about a foodstuff to form a gas-tight package. The walking beams move the respective boards and packages along the machine in synchronized manner into and out of the sealing unit. The forming section forms the top boards with cup shaped recesses prior to delivery to the sealing unit.

This application is a continuation-in-part application of application Ser. No. 548,517, filed May 9, 1966, now abandoned.

This invention relates to a packaging machine. More particularly, this invention relates to a machine and method for packaging foodstuffs. Still more particularly, this invention relates to a machine and method for packaging a series of product foodstuffs in sequential order.

Heretofore, packaging machines have been known which produce a series of separated packages of foodstuffs. However, these machines have relied upon packaging from materials which have been supplied thereto in endless strip form. For example, one type of these machines has utilized a continuously rotating wheel which has been supplied with a film which is subsequently vacuum formed into a series of interconnected pockets and a second film which is directed under the first formed film to enclose the pockets into a continuous laminated type strip. Subsequently, the strip is severed between the pockets into a plurality of individual packages. Another of these machines has utilized an endless conveyor which forms the bottom portion of a package from a continuous strip of film material which is vacuum formed into a series of pockets on the endless conveyor and the top portion of the package from a continuously supplied strip of film material which is adhered to the pocketformed bottom strip while on the endless conveyor. Subsequently, the continuously formed strip of enclosed pockets are severed into individual packages. Generally, these machines are operated in connection with a product supply means which introduces the foodstuffs into the cavities of the pockets immediately before the top and bottom strips of the packages are brought together.

These heretofore used machines and methods are cumbersome to use since they all must rely on a package which is formed from at least two strips of endless film Further, in several of these machine the product foodstulfs must be separately placed within the formed cavities of the first of the strips before the other can be placed thereover. Still further, where preprinted strips are used to form the packages, an objectionable amount of waste of the printed material occurs since not all of the preprinted surfaces of the strips are properly utilized.

In addition, these machines have been limited to a formation of a plastic type package which is subsequently provided by other devices with a rigid type material at least around the periphery of the formed package inorder to provide a more attractive package for the consumer as well as to allow display of the package on a rack.

Accordingly, it is an object of this invention to provide a machine and method for packaging a series of individually separated board supported product items in sequential arder.

It is another object of this invention to provide a machine and method for packaging a series of board supported product items into a series of vacuum sealed packages.

It is another object of this invention to provide a machine and method for packaging foodstuffs in a continuous manner.

It is another object of this invention to provide a machine and method for packaging foodstuffs in a sealed vacuum package.

It is another object of this invention to provide a machine and method for sequentially forming a series of packages of foodstuffs from individually supplied board portions and foodstufi portions.

It is another object of this invention to provide a machine and method of packaging foodstuffs in a simple rapid manner.

It is another object of this invention to provide a machine and method for forming a number of different types of packages for foodstuffs.

It is another object of this invention to provide a machine and method of forming a sealed package with a rigid board portion.

It is another object of this invention to provide a machine and method for forming self supporting packages for foodstuffs.

This invention provides a packaging machine and method for packaging foodstuffs in a simple economic manner. The foodstuffs to be packaged by the machine are delivered thereto on a bottom board and subsequently covered with a formed top board which is sealed to the bottom board so as to effect a one-piece package. Either or both of the bottom and top boards may be formed with a transparent central portion so as to permit a consumer toview the product encased within the package.

The machine comprises a product receiving end section for receiving a series of bottom board supported product items, a board transfer section adjacent the product receiving end section for placing a top board on each of the items of the series in sequential fashion, a sealer section downstream of the product receiving end section and board transfer section for pressure sealing the top board to the bottom board of each of the items of the series so as to form a complete sealed package, and a product dis charge end section for transferring the formed package from the sealer section out of the machine.

Additionally, the board transfer section of the machine forms the top board into a predetermined shape prior to placing the top board on the bottom board supported product items. Also, the sealer section allows for evacuation of air from between the top and bottom boards prior to the completion of a sealed package. In this latter regard, the sealer section alternatively allows for injection of an inert gas between the top and bottom boards immediately after evacuation of air and before completion of the sealed package.

The method of packaging the foodstuffs comprises the steps of delivering a series of bottom board product items to a first position, positioning a formed top board on each of the bottom supported product items in sequential fashion, evacuating the space between the positioned top and bottom boards, thereafter pressure sealing the top board to the bottom board to each of the items to form a series of packages in sequential fashion, and discharging the formed packages in sequential fashion to a pick-up position.

The invention thus provides a packaged foodstuff which is encased within a sealed vacuum type package which is self-supporting so as to be conveniently displayed for the consumer market. The package formed by the machine avoids any problem of wrinkling of the edges of the package since the preformed boards supplied to the machine are uniformly and proportionally positioned during the sealing process. Because the package is substantially rigid it, therefore, precludes any damage to the contained foodstuffs.

These and other objects and advantages of the invention will become more apparent in the following description taken in conjunction with the accompanying drawings in which:

FIG. 1 illustrates a perspective view of the packaging machine according to the invention;

FIG. 2 illustrates a partially broken plan view of the packaging machine of FIG. 1;

FIG. 3 illustrates a view taken on line 3-3 of FIG. 2;

FIG. 4 illustrates a side view of the product infeed conveyor and the infeed walkin beam of the packaging machine of FIG. 1;

FIG. 5 illustrates a view of the product infeed conveyor taken on line 55 of FIG. 4;

FIG. 6 illustrates a view of the drive end of the product infeed conveyor taken on line 66 of FIG. 4;

FIG. 7 illustrates a view taken on line 77 of FIG. 4;

FIG. 8 illustrates a view of the walking beam vertical movement means taken on line 8-8 of FIG. 4;

FIG. 9 illustrates a view of the tack seal assembly taken on line 99 of FIG. 4;

FIG. '10 illustrates a view of the board feed and transfer assembly taken on line 1010 of FIG. 2;

FIG. 11 illustrates a view of the board picker plate assembly taken in line 11-11 of FIG. 10;

FIG. 12 illustrates a cross sectional view of a picker plate taken on line 12-12 of FIG. 11;

FIG. 13 illustrates a view of the forming chamber taken on line 1313 of FIG. 10;

FIG. 14 illustrates a view of the forming chamber taken on line 1414 of FIG. 13

FIG. 15 illustrates a view taken on line 1515 of FIG. 13;

FIG. 16 illustrates a view of the sealer assembly taken on line 16-16 of FIG. 3;

FIG. 17 illustrates a view of the sealer assembly taken on line 17-17 of FIG. 16;

FIG. 18 illustrates a cross sectional view of a modified forming chamber according to the invention; and

FIG. 19 illustrates a fragmentary perspective view of a modified walking beam according to the invention.

Referring to FIG. 1, the packaging machine 20 cooperates with a product infeed conveyor 21 which is utilized to automatically deliver a series of product items 22 suitably placed on boards 23 to the packaging machine 20 to be packaged. Alternatively, any other suitable type of product infeed means can be substituted for the product infeed conveyor 21 to deliver a series of board supported product items 22 to the feed end of the packing machine 20. For example, the board supported product items 22 can be manually delivered to the packaging machine.

The packaging machine 20 is formed with a product receiving end section 24, a product discharge end section 25, a sealer section 26 intermediate the end sections 24, 25, a card magazine section 27 and a board transfer and forming section 28 located between the receiving end section 24 and card magazine section 27 upstream of the sealer section 26. The various operating components of the several sections of the packaging machine 20 are suitably driven by a suitable motor and drive assembly (not shown) located within a drive section 29 of the machine and actuated by a suitable switch console 30 on the top of the drive section 29.

In order to create an attractive aesthetic appearance as well as to provide a measure of safety to the packaging machine 20, suitable panel cover sections or guards 31 are secured to the frame of the machine to substantially enclose the interior of the machine except for the necessary protruding operating components.

As shown, the board supported product items 22 are delivered by the infeed conveyor 21 to the product receiving end section 24 of the packaging machine 20; thereafter, the received board supported items 22 are covered with suitable top cover boards 32 transferred and formed from the cards of the magazine section 27 adjacent the transfer and forming section 28. The covered product items 22 are then fed into the sealer section 26 where the boards 23 and 32 are secured to each other to completely enclose the product items 22 and thereby form a complete package 33. Next, the packages 33 are moved out of the sealer section 26 onto the product discharge end section 25 for discharging onto suitable package pick-up conveyors or hoppers (not shown).

Referring to FIGS. 2 and 3, the packaging machine 20 has a frame composed of a pair of vertical side plates 34 which are separated by and secured to a horizontal base plate 35; the base plate being mounted on suitable mounting pads 36. The vertical side plates 34 are further secured to a plurality of intermediate tie frames 37 which are disposed vertically on the base plate 35.

A cam shaft 38 is journaled in a plurality of suitable bearings 39 which are aifixed to suitable spacers 40 on each tie frame 37 and provided with a sprocket 41 suitably fixed thereto. A motor 42 of suitable construction is affixed to one of the side plates 34 to drive the cam shaft 38 through means of a suitable sprocket 43 fixed on the drive shaft 44 of the motor and chain 45 which meshes with the sprockets 41, 43.

The product receiving end section 24 of the machine 20 is provided with a pair of channel shaped stationary rails 46 which are suitably mounted longitudinally on the frame of the machine 20, a walking beam assembly 47 (FIG. 3) which includes three box shaped rails 48 interposed in alternating fashion with the stationary channel shaped rails 46 and which is operably connected to the cam shaft 38 for actuation thereby, and a product item detector 49, for example, a photoelectric cell, which scans the surface of thhe rails 48 of the walking beam assembly 47 to detect the presence of a board supported product item 22 thereon.

The sealer section 26 is provided with a heat seal assembly 50 which is secured within the side plates 34 of the frame of the machine 20 and straddles the projected path of the rails 48 of the walking beam assembly 47 as further described hereinafter. The heat seal assembly 50 is also operably connected to the cam shaft 38 for actuation thereby.

The product discharge end section 25, in like manner to the product receiving end section 24, is provided with a pair of channel shaped rails 51 which are secured to and project over the end of the frame of the machine 20 and which are in substantial alignment with the stationary rails 46, and a walking beam assembly 52 which includes three box shaped rails 53 interposed in alternating fashion with the stationary rails 51 and in substantial alignment with the walking beam rails 48 and which is operably connected to the cam shaft 38 for actuation thereby.

'Both the product receiving end section 24 and the product discharge receiving end section 25 are provided with a pair of suitable guide rails R (FIG. 2) which are spaced to guide the respective boards and packages 33 along the machine 20.

The board transfer and forming section 28 is provided with a transfer and forming assembly 54 which picks up a board 32 from a hopper 55 in the card magazine section 27, forms the board 32 into a suitable shape and transfers the shaped board onto a board supported product item 22 upstream of the heat seal assembly 50 and which is operatively connected to the cam shaft 38 for actuation thereby. Additionally, board transfer and forming section 28 can be provided with a suitable tack seal assembly 56- to insure the relative positions of the boards. For example, such a tack seal assembly includes a pair of tack sealers 57 each of which is mounted to the vertical side plates 45 to project over and tack seal a portion of the edges of the boards 23, 32.

Referring to FIGS. 2, 4, and 6, the product infeed conveyor 21 is provided with a stationary table top 58 which has a pair of longitudinal slots 59 running the length of the conveyor 21, a pair of endless conveyor claims 60 each of which is disposed about a pair of suitable sprocket wheels 61 mounted on suitable rotatable shafts 62 and carries a plurality of equi-spaced lugs 63 thereon which project through the slots 59 of the table top 58, and a drive means 64 for driving the upper reaches of the conveyor chains 60 in a direction towards the packaging machine 20. The shaft 62 adjacent the packaging machine is journaled within a pair of suitable self-aligning bearings 65 in the infeed conveyor frame 65a and is provided on one end with a sprocket 66 suitably fixed thereon which is driven through an endless chain 67 by the drive means 64. The drive means 64 is operatively interconnected to and driven by a sprocket 68 fixed on the cam shaft 38 through means of a suitable right angle drive 69 operating at a suitable drive ratio, such as a 1:1 ratio.

The product infeed conveyor 21 is secured to the frame of the packaging machine 20 in order to insure alignment of the various cooperating components therebetween.

The table top 58 of the product infeed conveyor 21 is formed with a load plate portion 70 which extends the length of the conveyor 21 outwardly from the conveyor chains 60 and an elongated package stop 71 which is parallel to the conveyor chains 60 and spaced on an opposite side of the conveyor chains from the load plate portion 70 so as to provide a stop against accidental movement of the board supported items 22 past the conveyor chains 60 upon delivery thereto.

In addition, the table top portion 58' which is between the conveyor chains 60 andsupported independently of the remainder of the table top 58 on a plurality of suitable supports 72 attached to frame members 73 of the conveyor 21 extends outwardly of the remainder of the table top 58 into the plane of the packaging machine 20 in a cantilevered fashion.

Further, a suitable chain tensioning device (not shown) can be installed in the conveyor 21 to properly tension the conveyor chains 60.

The operation of the product infeed conveyor 21 is such that the board supported items 22, such as, shingled bacon strips, are fed manually or automatically onto the table top 58 against the package stop 71 and over the table top portion 58' between a pair of adjacent sets of lugs 63. The conveyor chains 60 which are in continuous motion cause the set of lugs 63 behind the item 22 to abut and push the item 23 towards the packaging ma chine 20 at an output rate controlled by the speed of the packaging machine. For example, with a spacing of 10 inches between lug sets and a conveyor chain linear speed of 300 inches per minute, the output of the infeed conveyor 21 would be 30 packages per minute.

Referring to FIGS. 4, 7 and 8, the walking beam assembly 47 in the product receiving end section 24 of the packaging machine 20 is arranged to cooperate with the product infeed conveyor 21 so that with the stationary rails 46 in approximate axial alignment with the conveyor chains 60 the outside walking beam rails 48 are to either side of the cantilevered table portion 58' and the intermediate walking beam rail 48 is in alignment with the cantilevered table portion 58'.

The stationary rails 46 are suitably secured by angle brackets 74 to frame members 75 of the packaging machine 20 which extend transversely across the machine and which are secured to the side plates 34.

The rails 48 of the walking beam assembly 47 are mounted on a pair of transverse box beams 76 which are secured to a one piece casting 77 for movement therewith. The casting 77 is slidably mounted on a pair of stationary horizontal shafts 78, 79 below the surface of the rails 48 for reciprocal movement longitudinally of the packaging machine.

The casting 77 is formed with an elongated generally tubular portion 80 having a pair of cylindrical end sections 81, each of which houses a suitable sleeve bearing 82 for sliding on the shaft 78, a rectangular intermediate body section 83 between the end sections 81, a pair of spaced ribs 84 which extend horizontally in a direction normal to the end section 81, and a Y-shaped strut 85 which is formed on the ends of the ribs 84 parallel to the tubular portion 80. The Y-shaped strut 85 is provided with two pairs of rotatable cam rollers 86, one at each end, which ride on the shaft 79 in oppositely disposed relation on the top and bottom planes thereof. The ribs 84 of the casting 77 are of a size sufficient to impart a degree of flexible rigidity to the casting 77, that is, should there be any Ivertical misalignment between the shafts 78 and 79, the ribs 84 Will resiliently distort without damage to the casting. Further, should there be any horizontal misalignment between the shafts 78 and 79, the rotatable cam rollers 86 will move relative to the shaft 79 without offering any restraining force thereto.

' The casting 77 is reciprocally actuated on the shafts 78, 79, by a rocker arm 87 which is pivotally mounted on one of the side plates 34 and operatively connected to the cam shaft 38. The rocker arm 87 is rotatably mounted by a pair of ball bearings 88 on a shouldered pivot pin 89 which is secured to the side plate 34 as by a bolt 90. In order topivot further support, the free end of the pin 89 is received within an aperture in a horizontal bar 91 which is secured to a pair of hexagonal bars 92 as by bolts each of which is mounted on the side plates 34 as by bolts (not shown). The upper end of the rocker arm 87 is provided with a rotatably mounted cam roller 93 which is slidably positioned within a track 94 in the intermediate body section 83 of the casting 77 and the lower end is provided with a rotatable cam roller 95 which is slidably positioned in a contoured cam track 96 of a drum cam 97. The drum cam 97 is fixedly secured to the cam shaft 38 for rotation therewith so that for each revolution of the cam shaft 38 the casting 77 is reciprocated through one cycle through the horizontally applied force of the rocker arm 87.

It is noted that as the rocker arm 87 pivots about the pin 89, the upper cam roller 93 slides vertically within the track 94 without imparting any vertical motion to the casting 77.

The vertical motion of the casting 77 and, consequently the walking beam assembly 47 is controlled through the mounting of the shafts 78, 79. Each of the casting mounting shafts 7 8, 79 are secured at one end in a casting frame 98 in cantilevered fashion, as by a suitable washer 99 and threaded bolt 100. The casting frame 98 is supported on a pair of spaced vertical shafts 101 and is secured thereto as by a threaded bolt and washer assembly 102. Each shaft 101 is slidably mounted by suitable sleeve bearings 103 in a pair of vertically spaced support frames 104, 105 which are secured to the side plates 34 of the machine in a suitable manner. In addition, each shaft 101 is fixedly secured to a tie support 106, such as by a split collar and bolt assembly 107, which carries a cam follower block 108 intermediately thereon.

The cam follower block 108 mounts a rotatable cam follower 109 thereon which projects outwardly thereof. The cam follower 109 is positioned within a cam track 110 in a contoured cam 111 which is fixedly secured to the cam shaft 38 for rotation therewith.

Thus, for each revolution of the cam shaft 38, the shafts 101 and, consequently, the casting 77, are reciprocated vertically through the vertically applied force of the cam follower block 108.

It is noted that the respective cam tracks 96 and 110 of the drum cam 97 and cam 11 are so related to each other that the casting 77 and, consequently, the walking beam rails 48, travel in a generally rectangular path with regard to a vertical plane passing therethrough. It is further noted that the corners of such a rectangular path are rounded since both vertical and horizontal motion are imparted to the casting 77 simultaneously at these points. Also, the path is traversed exactly once for each revolution of the cam shaft 38.

Further, the outside walking beam rails 48 are provided with longitudinally spaced pushers 112 while the intermediate walking beam rail 48 is free of any pushers, but it may have a frictional surface or suction cup means as discussed infra (cf. FIG. 19).

In operation, the walking beam assembly 47 is actuated by the cam shaft 38 in synchronism with the product infeed conveyor 21 to receive the board support items 22 from the conveyor 21 and advance each item 22 in a stepwise fashion through the product receiving end section 24 into the sealer section 26. The walking beam rails 48 are sized to project into the plane of the product infeed conveyor 21 astride the projecting table top portion 58 and are further profiled so as to permit a suitable clearance from the drive means 64 of the conveyor 21 (FIG. 4).

The operation of the walking beam assembly 47, for example, with a centerline spacing of 9.625 inches between pushers 112 and with a product infeed conveyor having lugs 63 on ten-inch spacings is such that the horizontal strokes of the walking beam rails 48 is 9.665 inches and the vertical movement imparted by cam track 110 is 0.500 inch. When the walking beam rails 48 are in the farthestmost position Within the plane of the product infeed conveyor 21, the edge of the rails 48 project past the sprocket wheels 61 and the top surfaces of the pushers 112 are spaced below the plane of the table 58. Thereafter, the walking beam rails 48 are moved upwardly to the extent of the vertical stroke so that a pair of pushers 112 project through the plane of the table slightly behind a pair of lugs 63. The relationship of the projecting pushers 112 to the lugs is such that the linear speed of the pushers 112 which are in a state of acceleration is faster than the linear speed of the lugs 63 puhing the board 23 and that the puher 112 abut and push the board away from the lugs 63 before the lugs 63 pass the top dead center of the sprocket wheels 61. This permits the lugs 63 to accelerate around the sprocket wheels 61 without interfering with the boards 23.

It is noted that the top surface of the walking beam rails 48 do not project out of the plane of the table 58. Further, it is noted that the cantilevered table portion 58' is spaced approximately /8 inch above the surfaces of the stationary rails 46 of the packaging machine 20.

As the walking beam assembly 47 continues to move the rails are directed in a horizontal direction to the limit of the horizontal stroke thereof. During this movement the pushers 112 push the board 23 from the surface of the cantilevered table portion 58' of the conveyor 21 onto the rails 48 of the walking beam assembly 47. Upon reaching the end of the stroke, the walking beam rails 48 are directed vertically downwardly below the advanced board 23 under the influence of cam 111. At this time, the advanced board 23 comes to a rest position on the stationary rails 46. Then the rails 48 are moved horizontally back to the initial position with the edge of the rails under and within the plane of the conveyor 21 and the cycle is repeated.

Upon the second cycling of the walking beam assembly 47, a second set of pushers 112 are projected through the plane of the stationary rails 46 slightly behind the advanced board 23. Initially, when in the lowermost position, the second set of pushers 112 is located in a vertical plane spaced behind the board a distance of about 0.041 inch. Thus, as the walking beam rails 48 are raised, the second set of pushers 112 pass through the plane of the stationary rails 46 behind the board 23 and due to the slight horizontal motion of the walking beam rails 48 near the top extent of the vertical movement against the board 23 immediately before the walking beam rails 48 project through the plane of the stationary rails 46.

The walking beam assembly 47 is continuously cycled so as to move an item 22 in step-wise manner along the stationary rails 46 into the sealer section 26.

Referring to FIGS. 2 and 10, the hopper of the card magazine section 27 can be of any suitable construction which is adapted to stack and deliver a plurality of suitable boards for forming the top portion of the package to be made. For example, the hopper 55 stacks a plurality of boards 32 in angular relation to the horizontal plane of the packaging machine 20. The hopper 55 is mounted on a pair of mounting brackets 113 which are adustable to change the vertical position of the hopper 55. The brackets 113 are secured to a cross member 114 of a frame 115 which is mounted on a side plate 34 to the packaging machine 20.

Any suitable means can be incorporated in the hopper 55 to permit individual discharge of the boards 32. In addition, other suitable means and, for example, a roller follower, may be incorporated in the hopper 55 to keep the boards in contact with each other and against the discharge means at the bottom of the hopper.

Referring to FIGS. 2, 10, 11 and 13, the board transfer and forming assembly 54 includes a picker plate assembly 116 and a mold forming assembly 117. The picker plate assembly 116 includes a picker plate .118 which is fixedly secured on a rotatable shaft 119 by a pair of brackets 120. The shaft 119 is journalled in a pair of arms 121 which are fixedly secured to a transfer shaft 122 which is suitably journalled in the frame 115. The rotatable shaft .119 has a sprocket 123 fixedly mounted on one end thereof which is operatively connected through a chain 124 to a sprocket 125 which is rotatably mounted on the transfer shaft 122 so that upon rotation of the arms 121 about the axis of shaft 122 the planar position of the picker plate relative to the hopper 55 is maintained.

The transfer shaft 122 has a drive sprocket 126 fixedly mounted thereon which is oscillated by a tensioned chain 127 which is connected at one end to a bell crank lever 128 having a cam follower 129 running on a suitably contoured cam 130 fixedly mounted on the cam shaft 38 and at the other end to a reciprocal piston 131 of an air spring cylinder 132. In addition, the transfer shaft 122 has a secured rotatably mounted sprocket 133 thereon which is fixedly secured to the sprocket 125. The second sprocket 133 has a chain 134 which oscillates the sprockets 125, 133 to cause pivoting of the picker plate assembly 116 about the axis of shaft 119 from an angular position to a horizontal position. The chain 134 is connected at one end to a suitable bell crank lever 135 having a cam follower 136 running on a suitably contoured cam 137 fixedly mounted on the cam shaft 38 and at the other end to a reciprocal piston 138 of an air spring cylinder 139.

Thus, for each revolution of the cam shaft 38, the picker plate arms 121 are reciprocated through an arc and the picker plate 118 is oscillated about the shaft 119. It is noted that the cams 130 and .137 are contoured relative to each other so as to allow the picker plate 118 to move away from the hopper 55 until it can be pivoted without interference from the hopper.

\Referring to FIGS. 11 and 12, the picker plate 118 is provided with a spaced pair of vacuum chambers 140 which are connected to a common vacuum conduit line 141 and which are disposed to abut and pick-up a board 32 in the hopper 55 for transfer to the mold forming position. Each vacuum chamber 140 is formed by a plate 142 secured to the picker plate 118 over a manifold recess 143 in one side thereof which is connected by a plurality of ports 144 to recesses 145 in a rubber block 146 inserted in the opposite side of the picker plate 118. The conduit line 14.1 is connected to any suitable vacuum means which creates a vacuum in the picker plate 118 during movement of the picker plate 118 from adjacent the hopper 55 to the mold position.

Referring to FIGS. 10, 13 and 14, the mold forming assembly 117 includes a stretch forming mold .147 of suit able shape fixedly mounted by a pair of brackets 148 on a shaft 149 which is rotatably mounted by anti-friction bearings 150 in a pair of arms 151. The arms 151 are connected together by a tube 152 which is positioned in fixed relation around a shaft 153 rotatably secured in the frame 115 and fixedly secured, as by a threaded bolt 154 to a sprocket 155 which is concentrically mounted in fixed relation to the shaft 153. The sprocket 155 meshes with the chain 127 for oscillation thereby through cam 130 upon actuation of the cam shaft 38.

The shaft 149 is provided with a fixedly mounted sprocket 156 which is connected to a 1:1 ratio through a chain 157 to a sprocket .158 which is fixedly mounted to the frame 115 as by a threaded bolt 159, in concentric relation to the shaft 153. Since the sprocket 158 is fixed against rotation, the stretch forming mold 147 is maintained in a horizontal parallel position relative to the machine 20. Additionally, suitable clamping means may be provided on the brackets 148 in order to provide an adjustment in the relative position of the mold 147.

The mold forming assembly 117 also includes a heat plate and clamp assembly 160 which is fixedly mounted in the frame 115 at the mold forming position by suitable brackets 161. The heat plate and clamp assembly 160 includes a heater plate 162 fixedly mounted by a pair of heat insulators 163 to a frame 164 and supported at the corners as, for example, by adjustable jack screws 165. The heater plate 162 is suitably heated through a cal-rod type heater (not shown) which is electrically supplied through a terminal block 166 secured on the frame 164. As an alternative, the heater plate 162 can be provided with a water cooled area contiguous to the peripheral area of the board, including, for example, the area of the board in the immediate vicinity of the rubber strip 183 or the resilient gasket that may be adhered on the bottom of side walls 175 in an alternative construction so as to prevent heat from being transferred to the board in this area. This will avoid any softening of a film and the film may, for example, be secured to the board in this area. In addition, the assembly 160 includes four clamps 167, each of which is mounted at a corner of the assembly, for clamping the board 32 transferred by the picker plate 118 to the surface of the heater plate 162. Each clamp 167 includes a bracket 168 fixed to the frame 164, a lever 169 pivotally mounted at one end to the top of the bracket 168; a clamp element 170 connected by a pin 171 to the lever 169 and an air cylinder 172 pivotally secured at one end to the bracket 168 having a threaded piston rod 173 threaded through the clamp element 170. Additionally, the heater plate 162 may include a plurality of board guides 162b, each of which may be secured at a corner to position a board 32 thereon for heating and vacuum forming.

It is noted that the heater plate 162 is supplied with a plurality of air passages 162a which are utilized to conduct air under the top board during molding so as to facilitate the formation of the board into the desired shape. Additionally, the air passages can be utilized to allow a vacuum to be applied therethrough to securely hold the boards 32 until the forming mold clamps the board to the heater plate 162 and to allow subsequent venting upon forming the board into the desired shape.

Referring to FIGS. 14 and 15, the stretch forming mold 147 is formed with an enlarged recess 174 within the side walls 175 thereof into which passes a central air passages 176 which is connected to a suitable vacuum line 177. A pair of opposite side walls 175 are each formed with an air passage 178 which is connected to a vacuum line 179. The air passage 178 includes a port 180 which communicates with a manifold groove 181 located above a recess 182 into which rubber strip 183 having suitable communicating apertures 184 is positioned. Alternatively and in place of the recess 182 with an inserted rubber strip 183, a resilient, for example, rubber gasket may be adhered or glued all about the opening of the mold cavity on the bottoms of side walls 175. This resilient ring gasket like rubber strip 183, has suitable apertures 184 connecting with the manifold groove 181 in order to hold and lift the formed top boards. The gasket in this variation for practicing the invention also facilitates a seal between the mold and the board in pulling a vacuum for the molding operation.

In addition, the mold 147 has a sheet metal baflle plate 185 secured in spaced relation near the base of the recess 174 by suitable screws 186 and a suitable female mold block 187 mounted within the recess to further control the shape and extent of the molded section of the top boards. The baffle plate 185 serves to distribute vacuum uniformly through the recess and to dissipate the heat generated by the board and transmitted by the block 187. It may be desirable to supplement the radiant cooling of the mold 147 with other cooling means. The block 187 may be provided with passages for conducting a coolant to cool the block and the film material after it has been molded to the shape of the recess in the block 187. This cooling helps to set the film material to enhance the stability of the molded shape and to hold any residual shrinking to a minimum to provide a deeper, more accurately dimensioned cup molded center section. The cooling water passages may be throughout the block 187 and particularly in the top portion thereof, and may be cooled by circulating water of approximately 10 C. In Water cooling the mold 147, it may be desirable to omit the baffle plate 185 so as to permit better heat transfer and dissipation.

The vacuum means of vacuum line 141 of the picker plate 118 is interconnected to the product item detector 49 on the side of the packaging machine 20 for actuation thereby upon detection of a board supported item 22. Accordingly, when an item 22 is detected, for example, between the stations which are three steps and four steps before the sealer section 26, a vacuum is applied to the picker plate 118 to pick up a board 32.

In operation, at the initiation of a cycle, the picker plate 118 initially rests against a board 32 in the hopper for about A of a cycle. Upon detection of a board supported item 22 passing along the rails 46 to the position located one step from the board transfer and molding section 28, a vacuum is applied to the picker plate 118 to lock a board 32 thereto. Then the picker plate 118 is moved a short distance away from the hopper 55 with the board 32 while remaining parallel thereto, as shown, by the rotation of the arms 121 about the transfer shaft 122 under the influence of the cam shaft 38 and cam 130 through the chain 127 and sprocket 126. As the arms 1 l 121 approach the mold forming position, the picker plate 118 is caused to rotate about the axis of shaft 119 into a position which is parallel to the surface of the heater 162 under the influence of the cam 137 through the chain 134 and sprockets 133, 123 and 125.

As the board 32 is brought down onto the heater plate 162, or on a cooled peripheral ring surrounding the heated portion of the heater plate 162, a vacuum may be applied through the heater passages 162a to hold the board thereon. After placement of the board on the heater plate surface, the vacuum in the picker plate 118 is released and the picker plate 118 begins to return to its initial position of rest against a board in the hopper and the mold forming assembly 117 is brought down over the board 32.

Next, the clamp elements 17 which are initially spaced from the heater plate 162 out of the plane of the board guides 16212 are brought down over the top surface edges of the side walls 175 of the mold 147 by the retraction of the pistons 173 into the air cylinders 172 and clamp the board to the heater plate 162 or cooled peripheral ring depending on the system used.

The board is then heated on the heater plate 162. The board which is of any suitable type as hereinafter described has a heat moldable center section which is centrally located on the heater plate 162. A slight air pressure may be provided through the vacuum line 177 to insure contact of the board on the heater plate, as indicated above.

Alternatively, when the heater plate is spaced from the moldable center section of the board 32 it is used to supply heat to the center section substantially by radiation. The spacing of the plate from the normal plane of the film should be according to the sag of the film during heating and before vacuum is applied so that the film will not sag down and touch the platen. In this alternative, and in rapid operation in which the temperature of the platen is maintained above the melting point of the film being used so that it is not feasible to allow the film to physically contact the platen, the raised portion of or attached to the heater plate around its peripheral area which holds the movable center portion of the board 32 away from the plate, may be cooled by passages containing water which may have a temperature of about C. The film will thus not be subjected to any contact with the heated platen and will remain cool throughout the clamping perimeter of the mold, and the film will be radiantly heated throughout its center section. For polyethylene the platen itself may be maintained at approximately 260 C., and the film temperature will reach at normal cycle speed a temperature of about C. during the period of forming.

Referring to FIG. 18, the mold forming assembly 117' can alternatively utilize a dished heater plate 162' in order to ensure that the barrier film of the board 32 upon heating and consequent sagging does not come into contact with the heated plate 162'. Further, by being dished, the heater plate 162' can be used to apply differential heat to the film on the board 32 so as to obtain a substantially uniform heat stretching of the film. This also allows a higher amount of heat to be applied to the film at the corners of the board about the opening in the board especially where flaps are formed on the board to project into the opening for subsequently supporting the cup formed by the film. As above, the heater plate 162' is heated as by a Calrod type heater 260 and is mounted on a unit 261 by adjustable jack screws 262. In addition, the unit 261 is H-shaped in cross section, as shown, in order to provide a cooled peripheral ring 263 to surround the heated portion of the heater plate 162' and has a passage 264 for a flow of cooling water for cooling the area contiguous to the area of the board in the assembly 117. The unit 261 is mounted by means of suitable legs 265 in a slidable manner within slots of a mounting bar 266 mounted on a pair of mounting brackets 267 fixed to the machine frame. The unit 261 is adjustable in the horizontal plane within two directions perpendicular to each other. Further, the radiant cooling of the mold 147' can be supplemented, as above, by providing a passage 268 for conducting a coolant such as water at about 10 C. through the top portion of the mold 147'. The passage 268 in this case has an inlet 269 at the top surface of the mold as shown.

After a sufficient degree of heat is imparted to the board 32, a rapid vacuum is applied through the central vacuum line 177 of the mold 147 to collapse the center section of the board into the recess 174. At the same time, the passages 16241 in the heater plate 162 either remain vented or are provided with air pressure to facilitate the molding of the board 32.

After the board is molded, the vacuum line 177 is cut off and the recess 174 vented and vacuum is applied through the vacuum line 179 to clamp the molded board to the side walls of the mold 147. The clamp elements 170 are then moved out of the plane of the mold 147 and the mold is transferred to a position over an item 22 on the stationary rails 46 which is positioned two steps from the sealer section 26.

During the time that the board is being molded, the item 22 which had been detected to initially effect the pick up of the board is moved by the walking beam assembly 47 from a position one step from the transfer and molding section 28 to a position normal thereto.

The mold '147 is moved from the heater plate 162 by the arms 151 which pivot about the shaft 153 under the influence of the cam 130 through the chain 127 which is suitably tensioned around an intermediate idler sprocket 188 rotatably mounted on the frame 115. Since the shaft 149 on which the mold 147 is mounted is rotated about its axis in 1:1 ratio with the sprockets 158, the mold 147 remains in a plane parallel to the surface of the heater plate 162 as well as the surfaces of the stationary rails 46 of the packaging machine 20.

Since the picker plate 118 and mold 147 are moved by the action of the same chain 127 and cam 130, the picker plate 118 is timed to replace a board on the heater plate '162 immediately after a molded board is removed therefrom by the mold 147. Further, the mold forming assembly 117 is timed in relation to the walking beam assembly 47 so that after an item reaches the position to which the transfer and section 28 is normal, for example, two steps from the sealer section, a molded board is brought down over the item.

It is noted that when an item is missing from the series of items, the detector 49 will detect such and will not allow a vacuum to be formed in the picker plate 118. Thus, a board 32 will not be picked from the hopper 55; however, the operation of the components of the board transfer and forming assembly 54 will continue in normal fashion. This places the machine on a supplydemand operation which is not effected by missing items in a series.

Referring to FIGS. 2 and 9, the tack seal assembly 56 which may be associated with the board transfer and forming section 2'8 of the packaging machine includes a pair of tack sealers 189 positioned astride the walking beam rails 48. Each tack sealer 189 is mounted to a side plate 34 by a suitable bracket 190 and includes a lever 191 pivotally mounted to the bracket 190, an air cylinder 1% pivotally mounted at one end to the bracket 190 having a piston 193 reciprocally mounted therein, seal bar 194 secured around the piston 193 and pivotally connected to the lever 191, and a heater bar 195 having an upwardly projecting pin 196 which is mounted on the bracket 190 below the seal bar 194.

In operation, the seal bars 194 are out of the plane of the items on the rails 46; however, after the molded board 32 is placed over the item 22, the piston 193 is retracted into the air cylinder 192 causing the seal bars 194 to move into contact with the board 32. Since the board 23 supporting the product overlies the pin 196 of the heater bar 19 5, a flow of heat is directed from the bar 195 to the pin 1'96 causing a tack seal between the boards 23, 32. After the tack seal is engaged, the mold 147 is returned to the mold forming position and the walking beam assembly 47 advances the tacked package to a position one step removed from the sealer section 26 where the package dwells before moving into the sealer section 26. It is noted that the seal bars 194 and mold 147 can be sized relative to each other so that the sides of the mold 147 adjacent the seal bars 194 have recesses into which the seal bars 194 project upon coming in contact with a board 32. This ensures that the board 32 remains on the walking beam assembly 47 when the mold 147 is returned to the mold forming position. That is, the seal bars 194 restrain the board from moving with the mold 147 due to any suction or cohesive force existing between the mold 147 and board 32.

Referring to FIGS. 3, 16 and 17, the heat seal assembly 50 includes a lower seal chamber 197 and an upper seal chamber 198. The lower seal chamber 197 has a recess which is defined by the side walls 199 of the chamber 197 and a depending central portion 201. The top surface of the side walls 199 are provided with a suitable resilient pad 200, such as, rubber for purposes as hereinafter described. A number of posts 202, for example, four, are press fitted into the bottom of the chamber 197 and extend upwardly to support a pair of package supports 203 above the plane of the side walls 199 in alignment with the stationary rails 46 of the receiving end section 24 of the machine 20. These package supports will absorb some heat from the seal bar units and will dissipate some heat through the posts 202 and the walls of the lower seal chamber 197. It has been found that to minimize any heat transfer to the packages, it is desirable under some conditions of operation to shape the package supports 203 to provide a narrow almost knife edge at the top of the posts 202 to support the boards. The lower portions of the posts 202 project a short distance below the bottom of the chamber 197 and are surrounded concentrically by compression springs 204 which serve to mount the lower chamber 197 on a horizontally disposed upper support 205 secured to the vertical side plates 34. The base of the central portion 201 is secured to a stop bar 206 the ends of which are formed with slots to envelop and abut against a pair of shouldered stop screws 207 threaded in the support 205 upon urging of the lower chamber 197 upwardly under the force of the compression springs 204.

A piston 208 of an air cylinder 209 is slidably mounted in a sealed manner in a sleeve bearing 210 located within the central portion 201 of the lower chamber 197 and is provided with a reduced end portion on which a spherical bearing 211 is mounted such as by a threaded screw 212. The bearing 211 mounts a 'sealer mounting plate 213 thereon in spaced relation to the bottom of the recess 199. The sealer mounting plate 213 is further mounted in relation to the spherical bearing 211 and piston 208 so as to be self-centering. Additionally, the mounting plate 213 is prevented from rotation since the posts 202 pass therethrough and since the plate 213 fits within the recess of the lower seal chamber 197.

The sealer mounting plate 213 mounts a lower seal bar 214 thereon which is shaped with a sealing surface corresponding to the desired shape of scaled periphery of the package to be sealed, for example, a rectangular shape, and which is centrally recessed. The lower seal bar 213 is secured to the mounting plate 213 through a plurality of threaded heat insulators 215 with the surface thereof in the same horizontal plane as the top surface of the pad 200 on the side walls 199 and is heated by any suitable means, such as Calrod type heater 216. In order to provide a suitable heat dissipation barrier, a pair of heat shields 217 are positioned between the lower seal bar 214 and the package supports 203 through suitable insulated connectors 218. Also, a pair of package edge guides 219 are secured to a pair of opposed walls of the seal bar 214 for centering a package therebetween.

The air cylinder 209 reciprocally supporting the lower seal bar 214 in the lower seal chamber 197 is mounted within the upper support 205 as well as a lower support 220 fixedly secured to the side walls 34 in slidable relation through the piston 208. The air cylinder 209 is secured to a rectangular guide roller base plate 211 through a pair of symmetrical disposed self-aligning bearings 222 in suitable fashion. Two opposed ends of the guide roller base plate 221 are each provided with a cam follower 223 which rides within a suitable track 224 secured on the lower support 220 so that the air cylinder is prevented from rotating about the longitudinal axis thereof while allowing a degree of misalignment of the guide roller base plate 221 from a horizontal plane. The other two opposed ends of the guide roller plate 221 are each provided with a depending mounting block 225 which mounts a rotatable cam follower 226 thereon. Each of the cam followers 226 runs in a suitable contoured inner matched closed cam track in a cam 227 which is fixedly secured on the cam shaft 38 in order to raise and lower the lower chamber 197.

The upper seal chamber 198 is secured on a pair of vertical shafts 228 which are slidably mounted by suitable hearings in the upper and lower supports 205, 220. One end of the chamber 198 is pivotally secured on one of the vertical shafts 228 while the other end of the chamber 198 is detachably secured to the other vertical shaft 228, as by a quick release pin (not shown), so that the chamber 198 can be horizontally pivoted about one of the vertical shafts to permit entry into the lower chamber 197. In order to prevent the upper chambers 198 from upward vertical movement on the vertical shafts 228, a suitable securing means, such as a threaded screw and washer assembly 229, is provided therebetween.

The upper seal chamber 198 includes an upper seal bar 230 having a sealing surface in a plane spaced above and within the plane of the bottom surface of the chamber 198 corresponding to the sealing surface of the lower seal bar 214 which is fixedly secured, as by insulated threaded bolts 231, therein in spaced relation. The upper seal bar 230 is heated, for example, by a Calrod type heater 232; however, where the lower seal bar 214 is heated, the upper seal bar 230 need not be heated as desired, or vice versa. A plurality of heat shields 233 are disposed on both sides of the upper seal bar 230 by suitable securing means to dissipate the heat transmitted towards the chamber 198 and the topside of the package between the chamber. The heat shields 233 may be constructed as an inverted heat reflecting box, to completely surround the molded center section of the top package board during the sealing. Preferably, this box construction is slidably mounted on bolts 233a and spring-biased downward so that its bottom edges lightly bear against the top package board around the inner periphery thereof.

Each of the vertical shafts 228 is provided with a lift block 234 which is fixedly mounted thereon and formed with a bored aperture facing the other vertical shaft 228. A lift frame 235 of an apertured rectangular shape having a pair of opposed cam followers 236, each of which is rotatably mounted in a depending cam follower mounting block 237 thereon, is mounted with each of the cam followers 236 in the aperture of a lock block 234.

The lift frame 235 also has a second pair of opposed cam followers 238 rotatably mounted thereon by suitable depending cam follower blocks 239 in transverse relation to the cam followers 236. Each of the cam followers 238 is received within a suitable matched contoured closed cam track in the cam 227 on the opposite side from the cam follower 226 in order to raise and lower the upper chamber 198.

Additionally, the heat seal assembly 50 is provided with a vacuum valve 240 which is connected to a suitable vacuum pump through a vacuum line 241 and a vent valve 242 which is connected to a suitable gas or air supply source. Both valves 240, 242 are mounted on the lower seal chamber 197 with suitable porting directly into the chamber.

The vacuum valve 240 is actuated through a poppet rod 243 which is connected to a rocker arm 244. The rocker arm 244 is pivotally mounted on a bracket 245 secured to a side plate 34 and connected to a link arm 246. The link arm 246 is pivotally secured to an arm 247 which is pivotally mounted on brackets 248 on the side plate 34 and urged in an upward direction by a compression spring 249 suitably mounted on the base plate 35 of the machine intermediately of the arm 247, as by a bracket 250 and a threaded adjustable rod 251 which is secured to the arm 247 and slides in the bracket 250. The arm 247 has a cam follower 252 rotatably mounted at the free end thereof which is guided by a suitably contoured cam surface of a cam 253 fixedly secured on the cam shaft 38 adjacent cam 227.

The vent valve 242 is actuated by an assembly similar to the assembly actuating the vacuum valve 240 and need not be further described. Similar components are indicated by primed reference characters in the drawings.

In operation, the walking beam assembly 47 moves the top and bottom boards, which may or may not be tack sealed together, depending on whether or not a tack seal assembly is incorporated in the packaging machine from the dwell position adjacent the sealer section 26 into the evacuation-seal chamber formed by the heat seal assembly 50. In this regard, it is noted that the ends of the walking beam rails 48 are contoured in stepwise fashion so as to provide suitable clearances upon entry and removal from the heat seal assembly 50. With the upper seal chamber 198 at the uppermost position, the walking beam rails 48 transfer the tack sealed package from the stationary rails 46 to the package supports 203 of the lower seal chamber 197. Then, the rails 48 are retracted from the chamber 197. During this time, the upper seal chamber 198 moves downwardly until contact is made with the resilient surface 200 of the lower seal chamber 197. However, the upper seal chamber 198 continues to move downwardly an additional A; inch forcing the lower seal chamber 197 to also move downwardly against the force of the springs 204 as well as the tack sealed package in order to insure a positively sealed chamber therebetween.

Next, the chamber formed between the sealed chambers 197, 198 is evacuated through the vacuum valve 240. During .this time, the upper seal bar 230 is in contact, or very close to contact with the top peripheral surface of the tack sealed package and all or almost all of the complete periphery of the package is open for evacuation. Also, during this time, the lower seal bar 214 is moved upwardly into close proximity of the tack sealed package.

Upon completion of the evacuation cycle, the lower seal bar 214 moves upwardly into contact with the package and overtravels inch. This overtravel is taken up by the relative movement of the air cylinder 209 to the piston 208 in order to create a sealing pressure between the seal bars 214, 230 on the boards 23, 32 of the package, for example, a sealing pressure of 50 p.s.i. The sealing pressure can be modified by changing the air pressure on the cylinder 209. At the same time, one or both of the seal bars is heated to effectuate a seal around the entire periphery of the package.

Upon clamping of the upper and lower seal bars together the vacuum valve 240 is closed and the vent valve 242 is opened to vent the chamber.

The lower seal bar 214 is then lowered to its initial position while the upper chamber and seal bar are raised. At the same time, the walking beam rails 53 of the product discharge section are injected into the heat seal assembly 50 to transfer the sealed package from the package supports 203 to the stationary rails 51.

It is noted that the vertical movements of the upper and lower chambers 197, 198 are controlled by the same cams 227 and that the respective cam tracks are oppositely disposed in each cam 227. Accordingly, since the movements of the chambers 197, 198 are opposite to each other during sealing, the forces imparted on the cams 227 are equal and opposite thereby avoiding undue stress on the cam shaft 38 and the bearings 39.

Referring to FIG. 2, the walking beam assembly 52 of the product discharge end section 25 of the packaging machine 20 is formed of identical components as the walking beam assembly 47 of the product receiving end section 24 of the packaging machine 20 with the exception that the walking beam rails 53 have no upstanding lugs thereon. The walking beam assembly 52 is mounted in the packaging machine 20 in an opposite hand manner from the walking beam assembly 47 and actuated in delayed sequence thereto. The walking beam rails 48 and 53 can be provided with frictional surfaces, such as, a rubberized cork surface, in order to maintain the packages thereon during travel and during changes in speed. In addit-ion, and for operation under difiicult conditions, as, for example, may be encountered in high-speed operation or in operation with boards that are warped, it may be desirable to provide the top surface of the intermediate walking beam rail 48' of the walking beam assembly 47 and the intermediate walking beam rail 53 of the walking beam assembly 52 of the product discharge end section with a resilient upper surface containing suction cup areas in the positions which will be occupied by the package boards. A vacuum is supplied to these cups by evacuating air from them through conduit means, or as described for other vacuum transfer units herein in connection with the unit 28, to hold the boards from the time just before the boards are picked up until just after the most forward board is deposited in the heat sealing unit. The suction cup grips are helpful not only in accelerating the boards but also in decelerating them to a precise stationary position.

Alternatively, referring to FIG. 19, the center rail 48' of each walking beam assembly can be provided with suction cups 270 which are supplied with a vacuum by evacuation of air through the rail 53' in a suitable manner to hold the boards or packages, as the case may be, from the time just before the boards are picked up until just after the boards are deposited on the stationary rails. Additionally, in order to guide the boards 23 along the product receiving end section 24 in a manner to prevent the edges of the boards 23 from curling or bending up, a pair of top guides 271, formed as by angles, are secured to the machine to project over and out from the guide rails R. Each of these top guides 271 are spaced vertically relative to the stationary rails 46 to overlie the side edges of the boards 23 resting on the rails 46. Thus, as the rails 48 of the walking beam and cooperating pushers 112 move the boards 23 along the section 24, the boards 23 slide along and between the stationary rails 46 and top guides 271.

The walking beam rails 53 project over the end of the frame so that the packages placed thereat can be stripped by a suitable conveyor. In addition, the rails 53 can be dimensioned so that a package in its last position overhangs the edges of the rails 53 so that the package may fall by gravity into a suitable hopper thereunder.

It is noted that the packages are stepped through a number of positions on the walking beam rails 53 before stripping, Hence, these positions can be used for secondary operations on the packages, such as, code-dating, punching of holes in the boards for display, embossing of the establishment mark, etc.

It is further noted that the operation of the packaging machine components is completely synchronized such 

